This invention relates to sawmill operation. In such operations, raw logs (which might be rather large and heavy) are placed on a moving carriage, which moves the log back and forth in a straight line through the saw for the purpose of sawing off successive slices from the log. Typically the carriage travels along rails.
Conventional carriages employ 3 or 4 “knee” assemblies on the carriage, the knees being in spaced apart positions along the length of the carriage and against which the back side of the log (relative to the saw blade) rest. These knee assemblies also include devices to grip and hold the log in position. So, it may be understood that the knees operate as the back rests and grips to secure the log in position to the carriage. The multiple knees spaced along the carriage enable the carriage to grip and process logs of different lengths. As portions of the logs are sawed off, the knees move the log so that at the next pass of the carriage past the log will again be positioned to saw off yet another board. This back and forth motion of the carriage relative to the saw and the incremental moving of the log face into the plane of the saw blade will continue until the log is completely processed, whereupon the carriage will be loaded with the next log and scanning and sawing of that next log will proceed.
A typical operation is that the log is placed on the carriage and rotated to an optimal position for beginning cutting based on a pre-scan of the log to determine its shape. Further scanning is typically made while the log is on the carriage to further employ in software determining how best to cut the log. With such conventional carriages, each knee obscures a portion of the log from the scanner, so interpolation or smoothing is done to “remove” the knee from the scan and fill in what is presumed to be the configuration of the log in the obscured portion. Such smoothing can result in inaccurate information, if the portion of the log hidden by the knees does not conform to the assumptions of the smoothing algorithms.